What division of the autonomic nervous system prepares the body for 'fight or flight' responses?

The division of the autonomic nervous system that prepares the body for 'fight or flight' responses is the sympathetic nervous system. This system activates physiological changes that are critical for survival during stressful situations. When faced with perceived threats, the sympathetic nervous system triggers the release of adrenaline (epinephrine) from the adrenal glands. This leads to a series of reactions including increased heart rate, dilation of airways, and redistribution of blood flow to muscles, all designed to enhance the body's ability to react quickly and effectively to danger.

In contrast, the parasympathetic nervous system is responsible for 'rest and digest' functions, promoting relaxation and conservation of energy after the threat has passed. The central nervous system, while crucial for processing information and sending commands, does not directly manage the autonomic responses involved in 'fight or flight.' The somatic nervous system controls voluntary movements and is not involved in autonomic responses, focusing instead on skeletal muscle control. Thus, the sympathetic nervous system is distinctly identified as the system that primes the body for immediate physical action in stressful scenarios.